
Where an assumption of unidirectionality in causal effects is unrealistic, ′recursive′ models cannot be used, and more complex ′nonrecursive′ models are necessary. Unfortunately, many nonrecursive models (unlike recursive models) are ′unidentified′,...

Where an assumption of unidirectionality in causal effects is unrealistic, 'recursive' models cannot be used, and more complex 'nonrecursive' models are necessary. Unfortunately, many nonrecursive models (unlike recursive models) are 'unidentified', which makes meaningful parameter...